[PATCH v2 1/1] pinctrl: baytrail: Rectify debounce support

[PATCH v2 1/1] pinctrl: baytrail: Rectify debounce support

[Andy Shevchenko]

The commit 658b476c742f ("pinctrl: baytrail: Add debounce configuration")
implements debounce for Baytrail pin control, but seems wasn't tested properly.

The register which keeps debounce value is separated from the configuration
one. Writing wrong values to the latter will guarantee wrong behaviour of the
driver and even might break something physically.

Besides above there is missed case how to disable it, which is actually done
through the bit in configuration register.

Rectify implementation here by using proper register for debounce value.

Fixes: 658b476c742f ("pinctrl: baytrail: Add debounce configuration")
Cc: Cristina Ciocan <cristina.ciocan@intel.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
---
 drivers/pinctrl/intel/pinctrl-baytrail.c | 28 +++++++++++++++++-----------
 1 file changed, 17 insertions(+), 11 deletions(-)

diff --git a/drivers/pinctrl/intel/pinctrl-baytrail.c b/drivers/pinctrl/intel/pinctrl-baytrail.c
index 71bbeb9321ba..079015385fd8 100644
--- a/drivers/pinctrl/intel/pinctrl-baytrail.c
+++ b/drivers/pinctrl/intel/pinctrl-baytrail.c
@@ -1092,6 +1092,7 @@ static int byt_pin_config_get(struct pinctrl_dev *pctl_dev, unsigned int offset,
 	enum pin_config_param param = pinconf_to_config_param(*config);
 	void __iomem *conf_reg = byt_gpio_reg(vg, offset, BYT_CONF0_REG);
 	void __iomem *val_reg = byt_gpio_reg(vg, offset, BYT_VAL_REG);
+	void __iomem *db_reg = byt_gpio_reg(vg, offset, BYT_DEBOUNCE_REG);
 	unsigned long flags;
 	u32 conf, pull, val, debounce;
 	u16 arg = 0;
@@ -1128,7 +1129,7 @@ static int byt_pin_config_get(struct pinctrl_dev *pctl_dev, unsigned int offset,
 			return -EINVAL;
 
 		raw_spin_lock_irqsave(&vg->lock, flags);
-		debounce = readl(byt_gpio_reg(vg, offset, BYT_DEBOUNCE_REG));
+		debounce = readl(db_reg);
 		raw_spin_unlock_irqrestore(&vg->lock, flags);
 
 		switch (debounce & BYT_DEBOUNCE_PULSE_MASK) {
@@ -1176,6 +1177,7 @@ static int byt_pin_config_set(struct pinctrl_dev *pctl_dev,
 	unsigned int param, arg;
 	void __iomem *conf_reg = byt_gpio_reg(vg, offset, BYT_CONF0_REG);
 	void __iomem *val_reg = byt_gpio_reg(vg, offset, BYT_VAL_REG);
+	void __iomem *db_reg = byt_gpio_reg(vg, offset, BYT_DEBOUNCE_REG);
 	unsigned long flags;
 	u32 conf, val, debounce;
 	int i, ret = 0;
@@ -1238,36 +1240,40 @@ static int byt_pin_config_set(struct pinctrl_dev *pctl_dev,
 
 			break;
 		case PIN_CONFIG_INPUT_DEBOUNCE:
-			debounce = readl(byt_gpio_reg(vg, offset,
-						      BYT_DEBOUNCE_REG));
-			conf &= ~BYT_DEBOUNCE_PULSE_MASK;
+			debounce = readl(db_reg);
+			debounce &= ~BYT_DEBOUNCE_PULSE_MASK;
 
 			switch (arg) {
+			case 0:
+				conf &= BYT_DEBOUNCE_EN;
+				break;
 			case 375:
-				conf |= BYT_DEBOUNCE_PULSE_375US;
+				debounce |= BYT_DEBOUNCE_PULSE_375US;
 				break;
 			case 750:
-				conf |= BYT_DEBOUNCE_PULSE_750US;
+				debounce |= BYT_DEBOUNCE_PULSE_750US;
 				break;
 			case 1500:
-				conf |= BYT_DEBOUNCE_PULSE_1500US;
+				debounce |= BYT_DEBOUNCE_PULSE_1500US;
 				break;
 			case 3000:
-				conf |= BYT_DEBOUNCE_PULSE_3MS;
+				debounce |= BYT_DEBOUNCE_PULSE_3MS;
 				break;
 			case 6000:
-				conf |= BYT_DEBOUNCE_PULSE_6MS;
+				debounce |= BYT_DEBOUNCE_PULSE_6MS;
 				break;
 			case 12000:
-				conf |= BYT_DEBOUNCE_PULSE_12MS;
+				debounce |= BYT_DEBOUNCE_PULSE_12MS;
 				break;
 			case 24000:
-				conf |= BYT_DEBOUNCE_PULSE_24MS;
+				debounce |= BYT_DEBOUNCE_PULSE_24MS;
 				break;
 			default:
 				ret = -EINVAL;
 			}
 
+			if (!ret)
+				writel(debounce, db_reg);
 			break;
 		default:
 			ret = -ENOTSUPP;
-- 
2.11.0

Re: [PATCH v2 1/1] pinctrl: baytrail: Rectify debounce support

[Mika Westerberg]

On Tue, Jan 10, 2017 at 04:38:52PM +0200, Andy Shevchenko wrote:
> The commit 658b476c742f ("pinctrl: baytrail: Add debounce configuration")
> implements debounce for Baytrail pin control, but seems wasn't tested properly.
> 
> The register which keeps debounce value is separated from the configuration
> one. Writing wrong values to the latter will guarantee wrong behaviour of the
> driver and even might break something physically.
> 
> Besides above there is missed case how to disable it, which is actually done
> through the bit in configuration register.
> 
> Rectify implementation here by using proper register for debounce value.
> 
> Fixes: 658b476c742f ("pinctrl: baytrail: Add debounce configuration")
> Cc: Cristina Ciocan <cristina.ciocan@intel.com>
> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

Now it looks perfect, thanks!

Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com>

Re: [PATCH v2 1/1] pinctrl: baytrail: Rectify debounce support

[Linus Walleij]

On Tue, Jan 10, 2017 at 3:38 PM, Andy Shevchenko
<andriy.shevchenko@linux.intel.com> wrote:

> The commit 658b476c742f ("pinctrl: baytrail: Add debounce configuration")
> implements debounce for Baytrail pin control, but seems wasn't tested properly.
>
> The register which keeps debounce value is separated from the configuration
> one. Writing wrong values to the latter will guarantee wrong behaviour of the
> driver and even might break something physically.
>
> Besides above there is missed case how to disable it, which is actually done
> through the bit in configuration register.
>
> Rectify implementation here by using proper register for debounce value.
>
> Fixes: 658b476c742f ("pinctrl: baytrail: Add debounce configuration")
> Cc: Cristina Ciocan <cristina.ciocan@intel.com>
> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

Patch applied for fixes with Mika's ACK.

Yours,
Linus Walleij